1. Field of the Invention
The present invention relates to a process for preparing a radiation sensitive compound and a positive resist composition comprising said radiation sensitive compound which is produced by the process of the present invention.
2. Description of the Related Art
Hitherto, as a radiation sensitive component of a positive resist composition, a condensation product of a phenol compound and a quinone diazide sulfonyl halide has been used. When a hydroxyl group of the phenol compound is present near a group having a large steric hindrance or a ratio of the quinone diazide sulfonyl halide to the phenol compound is increased, a condensation reaction takes a long time in a solvent having a low relative dielectric constant. Depending on a kind of a sensitizer, a produced compound is precipitated in the solvent having the low relative dielectric constant. To solve such problems, it is proposed to increase an amount of a basic catalyst such as triethylamine. Though the increase of the catalyst amount shortens the reaction time and overcomes the precipitation problem, the radiation sensitive compound is severely colored so that resolution of a resist composition containing such compound is decreased.